Adequate nitrogen in the contents of soil is necessary for a healthy lawn, plants, and crops. Fertilizers containing nitrogen are used to enhance the nitrogen levels in the soil to produce greener, lusher, faster-growing plants, lawns, and crops. Nitrogen must be available for the plant to use it, meaning that the nitrogen must be converted to NH4+ or NH3. The Nitrogen may be readily available or organisms in the soil must covert the Nitrogen into a usable form.
Inorganic fertilizers, while inexpensive and easy to apply, tend to wash the nutrients out of the soil, requiring reapplication on a regular basis. Additionally, since inorganic fertilizers are concentrated, they tend to burn plant roots more than organic materials.
Fertilizers that are derived from an organic source are preferable for a variety of reasons. They have a lower burning potential and a lower leach potential; and they replenish the soil with micro-nutrients, essential amino acids, and organic matter that were consumed by previous agricultural and horticultural activity. However, most fertilizers derived from an organic source have a nitrogen content that is less than 3% and the Nitrogen is usually in a slow release form. The slow release nitrogen in most fertilizer derived from an organic source must be broken down over time by microorganisms in the soil in order for that nitrogen to be converted to a form that is usable by plants and crops. This element of organic-derived fertilizer pushes many to purchase synthetic fertilizers that provide a higher level of nitrogen and a quicker release into the soil and uptake by the plant.